TWI906581B - Post etching residues cleaning solution with titanium nitride removal - Google Patents

Abstract

The present invention relates to a composition capable of achieving high TiN etching and removal of organic polymers and residues without damaging Cu, Co and/or Ru or risking the damage of other materials present in the structure, e.g. low-k materials, said composition comprising: a) an organic amine; b) one or more inhibitor(s); c) one or more buffer(s); d) an activator; e) one or more glycol ether(s); f) optionally an aprotic solvent; and g) water. The present invention also relates to a kit comprising said composition in combination with an oxidizer, and the use thereof.

Description

Post-etching residue cleaning solution that can remove titanium nitride.

This invention relates to an assembly for post-implantation, post-etching/etching, and post-ash treatments in the semiconductor/IC manufacturing field. More specifically, this invention relates to an assembly that exhibits excellent cleaning properties against fluorocarbon (CFx) polymers and organic residues, and is capable of completely removing or reducing hard metal masks (e.g., titanium nitride (TiN)) while protecting Cu, Co, and Ru as interconnecting linings, caps, or barrier layers.

Integrated circuits (ICs) consist of millions of active devices formed in or on a silicon substrate. Initially isolated, these active devices are combined to form functional circuits and components. These devices are interconnected using well-known multi-layer interconnects. Interconnect structures typically have a first metallization layer, an interconnect layer, a second metallization layer, and, in recent years, a third and subsequent metallization layer.

In semiconductor/IC manufacturing, post-etching residue (PER) is typically removed using a wet cleaning process. A solution containing a complexing agent and water can be used in this process. Furthermore, selective etching of different layers within the microelectronic structure is considered a key and crucial step in IC manufacturing.

High TiN etching rates are desired in the first and subsequent metallization layers, and high-level oxidants are required to achieve this. Furthermore, the dry etching steps used in multiple patterning processes generate heavy fluorocarbon (CFx) polymers, which are very difficult to remove from the IC structure surface. Therefore, oxidants are also needed to decompose the CFx polymers. In the subsequent metallization layers, which mainly consist of copper (Cu-plugs), it is desirable to etch TiN at a rate that does not significantly damage the copper plugs. Depending on the thickness of both the TiN and metal layers (which largely depends on the integration scheme used), a solution capable of adjusting the etching rates of both TiN and the metal is needed.

It should be understood that the presence of an oxidizing agent (such as hydrogen peroxide) in the formulation may be necessary to achieve a sufficiently high TiN etching rate. However, the increased etching rates of copper and related metals (e.g., Co, Cu, and Ru corrosion) by the addition of oxidizing agents such as hydrogen peroxide is an undesirable effect. Therefore, a delicate balance must be struck between achieving a sufficiently high etching rate for TiN by removing the CFx polymer on one side and achieving a sufficiently low etching rate for metals (e.g., Cu, Co, and Ru) on the other side. To achieve this, other components are added to the solution, such as corrosion inhibitors, activators, buffer components, and solvents.

Another issue is that as more and more wafers are cleaned, the reaction of TiN with oxidants (such as hydrogen peroxide) causes the pH of the solution to drop due to the formation of acidic reaction products (e.g., H₂TiO₃), which leads to a decrease in the TiN etching rate. This problem is related to the ability to recover components, which is very important and difficult to achieve in this field.

US7,919,445 relates to a novel solution for removing post-etching residue. Preferably, an imidazoline compound is added as a corrosion inhibitor for treating the wafer surface.

WO03060045 relates to aqueous compositions for removing photoresist, etching and ash residues, and contaminants from semiconductor substrates. A single corrosion inhibitor compound or a mixture of corrosion inhibitors, such as benzotriazole, benzoic acid, malonic acid, gallic acid, catechol, or ammonium malonate, can be used in the stripping and cleaning of the composition. WO03060045 does not use oxidants to etch TiN, nor does it discuss protection with Cu, Co, or Ru.

WO06138505 relates to dense fluid compositions, such as supercritical fluid compositions, for removing hardened photoresists, post-etching residues, and/or undercoating antireflective coatings from the surface of microelectronic devices. However, the fluid composition contains at least one fluoride source, which will impair low-k dielectric materials. WO06138505 does not relate to the etching of TiN or the protection of Cu, Co, or Ru.

Clearly, there is a need to find a composition that can achieve high TiN etching and remove CFx polymers without damaging Cu, Co, or Ru, and without the risk of damaging other materials present in the structure (e.g., low-k materials). Furthermore, it is necessary to address the frequently observed decrease in TiN etching rate due to increased wafer loading caused by reaction product accumulation, thereby enabling the recovery of the composition for continued use (in a recycle mode). This objective can be achieved through the composition of this application.

Therefore, the present invention provides a recyclable composition capable of removing high TiN etching and CFx polymers with minimal or no etching of Cu, Co, and Ru, or without risk of damage to other materials present in the structure (e.g., low-k materials), said composition comprising: a) an organic amine; b) one or more inhibitors; c) one or more buffers; d) an activator; e) one or more glycol ethers; f) an optional aprotic solvent; g) water.

Another aspect of the invention is to use the above-described composition in combination with an oxidizing agent to regulate the etching rate of Cu/Co/Ru and TiN and/or remove organic and/or inorganic residues, the preparation comprising: A) a composition comprising: a) an organic amine; b) one or more inhibitors; c) one or more buffers; d) an activator; e) one or more glycol ethers; f) an optional aprotic solvent; g) water; B) an oxidizing agent, such as hydrogen peroxide, ozone water, or persulfate.

Other objects, advantages and novel features of the present invention will become more apparent from the accompanying figures and the detailed description below.

While this disclosure allows for various forms of implementation, preferred embodiments are described below. It should be understood that this disclosure should be considered as an example of this disclosure and is not intended to limit this disclosure to the specific embodiments shown.

In one embodiment of this application, the composition is prepared by mixing the following: a) an organic amine; b) one or more inhibitors; c) one or more buffers; d) an activator; e) one or more glycol ethers; f) an optional aprotic solvent; and g) water. This composition can be used to prepare agents that can adjust the etching rates of TiN and Cu/Co/Ru and remove polymer (residue) during semiconductor/IC manufacturing processes. For this purpose, an oxidant can be added to the composition.

Therefore, in another embodiment of this application, the preparation is prepared by mixing a) an organic amine, b) one or more inhibitors, c) one or more buffers, d) an activator, e) one or more glycol ethers, f) an optional aprotic solvent and g) water in any order, and then adding an oxidizing agent.

Then, the unpatterned wafer (TiN, Cu/Co/Ru, low k) or patterned wafer to be processed is broken into samples and then brought into contact with the prepared composition.

As shown in Figures 1 and 2, residue removal and TiN etching are performed simultaneously, and the etching rate of TiN and Cu/Co/Ru is controlled by changing the composition in the composition. Furthermore, any components remaining on the surface can be removed by rinsing with a suitable solvent or solvent mixture, such as water and/or isopropanol (IPA).

The combination of organic amines with oxidants can make polymers more soluble in water. In addition, organic amines can stabilize oxidants, making the recycling and reuse of the composition possible. Organic amines may be selected from the following: 1-methylimidazolium; imidazolium; pyrazole; 4-acetomorpholine; N-methoxymorpholine; 1,3,5-tris(dimethylaminopropyl)-hexahydrotriazine; 4-methylpyridine N-oxide; 2-methylpyridine N-oxide; 4-methoxypyridine N-oxide hydrate; 4-chloropyridine N-oxide; 8-methylquinoline N-oxide; 1-dodecaneamine, N,N-dimethyl-N-oxide; 4-methylmorpholine 4-oxide; 1-tetradecaneamine, N,N-dimethyl-N-oxide; (C ₁₀ -C ₁₆ )alkyldimethylamine oxide; (C _12-18 )alkyldimethyl-N-oxide; pyridine 1-oxide; decylamine, N,N-dimethyl-N-oxide; hexadecaneamine, N,N-dimethyl-N-oxide. Preferably, the organic amine can be selected from 4-methylmorpholine 4-oxide and 1,3,5-tris(dimethylaminopropyl)-hexahydrotriazine.

The amount of organic amine present in the composition of the present invention, based on the total weight of the composition, can range from 0.01 to 25 wt%, preferably from 0.1 to 15 wt%.

In a preferred embodiment, the amount of 4-methylmorpholine 4-oxide present in the composition as an organic amine, based on the total weight of the composition, ranges from 0.5 to 20 wt%, preferably from 5 to 20 wt%, and most preferably from 8 to 15 wt%. For example, the amount of 4-methylmorpholine 4-oxide present in the composition as an organic amine, based on the total weight of the composition, is 8 wt%.

The inhibitor is a corrosion inhibitor of Cu, Co, or Ru, and can be selected from compounds called polyethyleneimine (class a), azoles (class b), and their derivatives. The etching rate of each compound can be controlled by changing the functional groups in each type of inhibitor.

(A) Polyethyleneimine: BASF Lupasol® FG, G20, G35, G100, PR8515, HF, P, PS, PO100, PN 50, PN 60, SK;

(B) Azides: Histidine, adenosine, adenine; pyridine; benzo[a]isodiazole; 2,2'-bipyridine;4,4'-bis(chloromethyl)-2,2'-bipyridine;1,2,3-triazole;1,2,4-triazole;tetrazolium; pentaazole, 1,3,4-oxadiazole; oxadiazole, 1,2,3-oxadiazole; 1,2,5-oxadiazole; 1,2,4-oxadiazole; thiazole; 1,2,3-thiadiazole; 1,2,4-thiadiazole; 1,2,5-thiadiazole; 1,3,4-thiadiazole; benzo[a]triazole (BTA); 5-alkylbenzo[a]triazole (alkyl= _{-CnH2n +1} , where n=1-6); 6-alkylbenzo[a]triazole (alkyl= _{-CnH2n +1)} (where n=1-6); 5-amino-benzotriazole; 6-amino-benzotriazole; 1-(methoxymethyl)-1H-benzotriazole; 1H-benzotriazole-1-methanol; 1-(chloromethyl)-1H-benzotriazole; 5-phenyl-benzotriazole; N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methylamine; N,N-bis(2-ethylhexyl)-5-methyl-1H-benzotriazole-1-methylamine; 2,2'-[[(5-methyl-1H-benzotriazole-1-yl)methyl] [Imino] diethanol; 5-nitro-benzotriazole; benzotriazole carboxylic acid; 1-amino-1,2,4-triazole; hydroxybenzotriazole; 2-(5-amino-pentyl)-benzotriazole; 1-amino-1,2,3-triazole; 1-amino-5-methyl-1,2,3-triazole; 3-amino-1,2,4-triazole; 5-amino-1,2,4-triazole; 3-isopropyl-1,2,4-triazole; 3,5-diamino-1,2,4-triazole; 5-phenyl sulfide benzotriazole; 5-halo-benzotriazole (halo= F, Cl, Br or I); 6-halogen-benzotriazole (halogen = F, Cl, Br or I); naphthotriazole; 4-methyl-2-phenylimidazolium; 5-aminotetrazole; pentylenetetrazolium; 5-phenyl-1H-tetrazole; 5-benzyl-1H-tetrazole; 5-methyltetrazole; 2-benzylpyridine; 2,4-diamino-6-methyl-1,3,5-triazine; methyltetrazole; imidazolinone;

1,5-Pentanetetrazole, imidazolinethione; 4-Amino-4H-1,2,4-triazole; benzothiazole; benzimidazole.

The amount of inhibitor present in the composition of the invention, based on the total weight of the composition, can range from 0.01 to 6 wt%, preferably from 0.5 to 2 wt%.

In preferred embodiments, the amounts of BTA and 6-methylbenzotriazole present as inhibitors in the composition, based on the total weight of the composition, range from 0.1 to 6 wt% and 0.01 to 5 wt%, preferably 0.5 to 3 wt% and 0.1 to 2 wt%, and most preferably 0.8 to 2 wt% and 0.5 to 1 wt%. For example, the amounts of BTA and 6-methylbenzotriazole present as inhibitors in the composition, based on the total weight of the composition, are 1 wt% and 1 wt%, respectively.

Chemical equation 1 presents one of the possible reaction equations for the oxidation and etching of TiN in the presence of hydrogen peroxide. _{The H₂TiO₃} formed in this process is acidic. Furthermore, the ammonia formed during the reaction evaporates. Both of these processes contribute to a stable decrease in the pH of the solution, which leads to variations in the etching rates of TiN and the metal. (Chemical Reaction 1)

Furthermore, according to chemical equations 2 and 3, hydrogen peroxide can decompose by reacting with ^Ti⁴⁺ ions, releasing more protons and further lowering the pH of the composition: (Chemical Reaction 2) (Chemical Reaction 3)

To stabilize the etching rate of TiN, the effects of acid accumulation and ammonia evaporation must be compensated for to ensure the pH stability of the composition. For this purpose, the concept of a pH buffer can be applied to this mechanism, and a buffer system can be incorporated into the composition.

The buffer components may be selected from the following: ammonium hydroxide; phosphoric acid; tetramethylammonium hydroxide (TMAH); tetraethylammonium hydroxide (TEAH); tetrabutylammonium hydroxide; methanolamine (MEA); ethanolamine (DEA); triethanolamine (TEA); polyethylene glycolamine; diethylene glycolamine; triethylene glycolamine; 1,3,5-tris(dimethylaminopropyl)-hexahydrotriazine.

The amount of buffer present in the composition of the invention, based on the total weight of the composition, can range from 0.01 to 5 wt%, preferably from 0.5 to 2 wt%.

In preferred embodiments, the amounts of ammonium hydroxide and disodium hydrogen phosphate present as buffers in the composition, based on the total weight of the composition, range from 0.01 to 1 wt% and 0.01 to 5 wt%, respectively; more preferably, from 0.05 to 0.7 wt% and 0.1 to 2 wt%; and most preferably, from 0.1 to 0.5 wt% and 0.5 to 1.5 wt%. For example, the amounts of ammonium hydroxide and disodium hydrogen phosphate present as buffers in the composition, based on the total weight of the composition, are 0.12 wt% and 1 wt%, respectively.

Buffers can also be used to control pH to prevent corrosion of some sensitive metals, such as Co at high pH. The inventors have found that the composition to be protected, when mixed with hydrogen peroxide in a pH window of 6.0 to 7.5, not only reduces corrosion of Cu, Co, and Ru, but also helps to minimize damage to dielectric materials (low-k films).

However, lowering the pH also reduces the oxidation potential of hydrogen peroxide, leading to an undesirable decrease in the TiN etching rate. In this field, relatively high concentrations of oxidants are typically required to achieve sufficiently high etching rates for metal hard masks. Surprisingly, the inventors have successfully discovered a series of activators to enhance the TiN etching rate at low pH conditions. Therefore, when activators (such as ammonium salts and quaternary ammonium salts) are added to the composition to initiate the TiN/oxidant reaction, the amount of oxidant is reduced while maintaining a high TiN etching rate. It is noted that some activators can also be used as components of the aforementioned buffer systems.

The activator can be selected from the following: ammonium methanesulfonate; ammonium dihydrogen phosphate (( _NH₄ ) _H₂PO₄ ); diammonium hydrogen phosphate ₍ diammonium phosphate, ( _NH₄ ) _₂HPO₄ ); ammonium phosphate (( _NH₄ ) _{₃PO₄ ) .} (), Triammonium citrate; Ammonium acetate; Ammonium ethylenediaminetetraacetate; Tetraammonium ethylenediaminetetraacetate; Trans-1,2-cyclohexylene diazonotetraacetate; Diethylenetriaminepentaacetate; Hydroxyethyl ethylenediaminetriacetate; Methylglycine diacetate; Triammonium diazonoacetate; Ammonium persulfate; Ammonium sulfate; Ammonium carbonate; Ammonium nitrate; Ammonium diborate; Ammonium carbamate; Ammonium fluoride; Ammonium hexafluorosilicone; Ammonium hexafluorotitanium; Ammonium metatungstate; Ammonium pentaborate; Ammonium tetrafluoroborate; Ammonium trifluoromethanesulfonate; Trans-1,2-cyclohexylene diazonotetraacetate; Tetramethylammonium ethylenediaminetetraacetate.

The amount of activator present in the composition of the invention, based on the total weight of the composition, can range from 0.01 to 3 wt%, preferably from 0.1 to 1 wt%.

In a preferred embodiment, the amount of trans-1,2-cyclohexylene diazonotetraacetic acid present as an activator in the composition, based on the total weight of the composition, ranges from 0.01 to 0.5 wt%, preferably from 0.05 to 0.3 wt%, and most preferably from 0.08 to 0.2 wt%. For example, the amount of trans-1,2-cyclohexylene diazonotetraacetic acid present as an activator in the composition, based on the total weight of the composition, is 0.3 wt%.

Partially water-miscible organic solvents can be used to reduce surface tension and increase surface wetting without any of the drawbacks associated with typical surfactants (such as strong physical adsorption to surfaces), and can help dissolve organic polymers and polymer residues (such as those containing -CFx, -CHx). Ethylene glycol ethers are specifically chosen as organic solvents and can be selected from the following: butyl ethylene glycol (BG), butyl diethylene glycol (BDG), butyl triethylene glycol, n-hexyl diethylene glycol, n-hexyl ethylene glycol, 2-hexyloxy-1-ethanol, tetrahydrofurfuryl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monobenzyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol diethyl ether, triethylene glycol monomethyl ether, di ...methyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl Alcohol monomethyl ether, triethylene glycol dimethyl ether, polyethylene glycol monomethyl ether, diethylene glycol methyl ethyl ether, triethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monobutyl ether, propylene glycol, monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoisopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol diisopropyl ether, tripropylene glycol monomethyl ether, 1-methoxy-2-butanol, 2-methoxy-1-butanol, 2-methoxy-2-methylbutanol, 1,1-dimethoxyethane and 2-(2-butoxyethoxy)ethanol.

The amount of glycol ether present in the composition of the present invention, based on the total weight of the composition, can range from 1 to 60 wt%, preferably from 10 to 50 wt%.

In a preferred embodiment, the amount of BDG present in the composition as an ethylene glycol ether, based on the total weight of the composition, ranges from 1 to 60 wt%, preferably from 10 to 55 wt%, and most preferably from 15 to 45 wt%. For example, the amount of BDG present in the composition as an activator, based on the total weight of the composition, is 30 wt%.

Optionally, an aprotic solvent is also used in the composition to facilitate the dissolution of other components in the composition and to improve the efficiency and solubility of organic residues removed from the wafer surface. The aprotic solvent (if present) may be selected from the following: dimethyl sulfoxide (DMSO), cyclobutane, propylene carbonate, dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), or mixtures thereof.

The amount of aprotic solvent (if present) in the composition of the invention may be from 1 to 50 wt, preferably from 5 to 25 wt, based on the total weight of the composition.

In a preferred embodiment, the amount of DMSO present in the composition as a solvent, based on the total weight of the composition, ranges from 1 to 50 wt%, preferably from 3 to 20 wt%, and most preferably from 5 to 15 wt%. For example, the amount of BDG present in the composition as an activator, based on the total weight of the composition, is 30 wt%.

What remains is water.

In another embodiment of the invention, an oxidizing agent may be added to a composition comprising a) an organic amine, b) one or more inhibitors, c) one or more buffers, d) an activator, e) one or more glycol ethers, f) an optional aprotic solvent, and g) water to form an preparation. The oxidizing agent may be selected from hydrogen peroxide ( _H₂O₂ ), _ozone water, or persulfate.

The oxidant may be added in the following volume ratios (including component a) to g) of the composition to oxidant: from 65:1 to 1:5 (about from 0.51 to 26.2 wt%), preferably from 33:1 to 1:52 (about from 1 to 21.3 wt%), and most preferably from 22:1 to 1:1 (about from 1.5 to 16.2 wt%).

In another embodiment of this application, a reagent kit is provided. The reagent kit comprises A) a composition and B) an oxidizing agent, said composition comprising: a) an organic amine; b) one or more inhibitors; c) one or more buffers; d) an activator; e) one or more glycol ethers; f) an optional aprotic solvent; and g) water.

In the semiconductor/IC manufacturing process, this reagent kit can be used to adjust the etching rate of Cu/Co/Ru and TiN, as well as to remove organic polymers and residues from the wafer.

The experiments and examples below illustrate the etching and etching rates of TiN and Cu/Co/Ru, and show the removal of organic polymers and residues.

Experiment:

A. Etching rate experiment:

Step 1. Unpatterned wafers (Cu/Co/Ru, TiN, low-k) or patterned wafers are selected from commercial sources.

Step 2. As shown in Figure 3, the wafer is broken into smaller samples 51.

Step 3. Measure the film thickness of the appropriate material:

1. For metals, use a 4-point probe or X-ray fluorescence (XRF) to measure layer thickness;

2. For non-metallic materials, the elliptical polarization method is used to measure the film thickness.

Step 4. Prepare preparation 52 as described below.

Step 5. Place formulation 52 into a hot-circulation vessel to reach a stable target temperature; the temperature used is similar to that used in common industrial processes (approximately 40 to 70°C). Stir the solution using a mechanical stirrer.

Step 6. The sample is secured in a mechanical holder.

Step 7. As shown in Figure 3, contact the sample with the solution for a period of time (usually 10 minutes).

Step 8. After a certain period of time, the contact between the solution and the sample is cut off. The sample is cleaned with ultrapure water or IPA or a water/IPA mixture for about 2 to 5 minutes.

Step 9. Dry the sample with _N2 gas and check to ensure that there is no water residue on the surface.

Step 10. Measure the residue thickness as described in Step 3.

Step 11. Calculate the etching rate as described below.

For example, when the thickness before the reaction is 330 Å, the thickness after the reaction is 300 Å, and the reaction time is 10 minutes, the etching rate is calculated as follows: Etching rate = (330 - 300 / 10 = 3 Å/min)

B. Evaluation of patterned chip surface residue composition

The steps are the same as in A, but steps 3, 10, and 11 are not performed.

Example:

The following examples are provided to allow for a better understanding of this disclosure. These examples should not be construed as narrowing the scope of this disclosure in any way.

Except for the addition of oxidizing agent in the volume ratio of the composition containing components a) to g) to the oxidizing agent, all percentage information in this specification is by weight percentage based on the total weight of the composition. It goes without saying that the sum of the amounts of components a) to g) added to the composition is 100%.

Following the steps outlined below, various examples are provided to illustrate this disclosure and to compare it with existing technologies.

Examples 1 to 6

The role of organic amines

In Examples 1 to 6, tetraammonium ethylenediaminetetraacetate (EDTA) is used as the activator, BDG as the ethylene glycol ether, DMSO as the aprotic solvent, and BTA as the inhibitor. In Examples 1-2, 3-4, and 5-6, imidazole, 1-methylmorpholine-4-oxide, or 1,3,5-tris(dimethylaminopropyl)-hexahydrotriazine are used as organic amines, respectively. The remainder is water. Table 1 Example 1 Example 2 imidazole 0.1 0.2 trans-1,2-cyclohexyl diazonium tetraacetate tetraammonium; (NH4)4-CDTA 0.1 0.1 BDG 35 35 DMSO 10 10 BTA 4 4 Composition: _{H₂O₂ volume} ratio 1:1 1:1 Cu E/R (Å/min) 4.2 4.2 Co E/R (Å/min) 1.2 2.1 TiN E/R (Å/min) 165 195 Example 3 Example 4 4-Methylmorpholine 4-oxide 10 12 Tetraammonium ethylenediaminetetraacetic acid 0.1 0.1 BDG 30 30 DMSO 10 10 BTA 4 4 Composition: _{H₂O₂ volume} ratio 1:1 1:1 Cu E/R (Å/min) 4 4.2 Co E/R (Å/min) 0.2 0.2 TiN E/R (Å/min) 168 174 Example 5 Example 6 1,3,5-Tris(dimethylaminopropyl)-hexahydrotriazine 3 5 Tetraammonium ethylenediaminetetraacetic acid 0.1 0.1 BDG 30 30 DMSO 10 10 BTA 4 4 Composition: _{H₂O₂ volume} ratio 1:1 1:1 Cu E/R (Å/min) 4.2 4.2 Co E/R (Å/min) 0.4 0.6 TiN E/R (Å/min) 168 174

The results in Table 1 show that TiN E/R increases with the amount of organic amine, and that the minimum Co and Cu E/R (Å/min) can be obtained by using appropriate organic amines.

Example 7-17

The role of activators

In Example 7-17, 4-methylmorpholine 4-oxide is used as an organic amine, BDG as an ethylene glycol ether, DMSO as an aprotic solvent, and BTA as an inhibitor. In Examples 7-9, 10-11, 12-13, 14-15, and 16-17, tetraammonium ethylenediaminetetraacetate, tetraammonium trans-1,2-cyclohexyl diazonium tetraacetate, triammonium citrate, ammonium acetate, or disammonium hydrogen phosphate are used as activators, respectively. The remainder is water. Table 2 Example 7 Example 8 Example 9 4-Methylmorpholine 4-oxide 10 10 10 Tetraammonium ethylenediaminetetraacetic acid 0 0.1 0.3 BDG 30 30 30 DMSO 10 10 10 BTA 4 4 4 Composition: _{H₂O₂ volume} ratio 1:1 1:1 1:1 Cu E/R (Å/min) 3.1 4.3 4.5 Co E/R (Å/min) 1.6 2.1 2.4 TiN E/R (Å/min) 100 168 220 Example 10 Example 11 4-Methylmorpholine 4-oxide 10 10 trans-1,2-cyclohexyl diazonium tetraacetate tetraammonium 0.1 0.3 BDG 30 30 DMSO 10 10 BTA 4 4 Composition: _{H₂O₂ volume} ratio 1:1 1:1 Cu E/R (Å/min) 4 4.2 Co E/R (Å/min) 2.1 2.4 TiN E/R (Å/min) 173 232 Example 12 Example 13 4-Methylmorpholine 4-oxide 10 10 Triammonium citrate 0.1 0.3 BDG 30 30 DMSO 10 10 BTA 4 4 Composition: _{H₂O₂ volume} ratio 1:1 1:1 Cu E/R (Å/min) 5.2 5.4 Co E/R (Å/min) 2.5 3.1 TiN E/R (Å/min) 145 157 Example 14 Example 15 4-Methylmorpholine 4-oxide 10 10 ammonium acetate 0.1 0.3 BDG 30 30 DMSO 10 10 BTA 4 4 Composition: _{H₂O₂ volume} ratio 1:1 1:1 Cu E/R (Å/min) 3.6 3.8 Co E/R (Å/min) 1.9 2.3 TiN E/R (Å/min) 155 192 Example 16 Example 17 4-Methylmorpholine 4-oxide 10 10 Diammonium hydrogen phosphate 0.1 0.3 BDG 30 30 DMSO 10 10 BTA 4 4 Composition: _{H₂O₂ volume} ratio 1:1 1:1 Cu 3.5 4.5 Co 1.8 2.1 TiN 157 201

The results in Table 2 show that TiN E/R is very low when no activator is used (Example 7), and TiN E/R increases significantly with increasing activator concentration.

Examples 18-24

The effect of inhibitors

In Examples 18-24, 4-methylmorpholine 4-oxide was used as the organic amine, trans-1,2-cyclohexyl diazonium tetraacetate as the activator, BDG as the glycol ether, and DMSO as the aprotic solvent. One or more of BTA, N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazol-1-methylamine, N,N-bis(2-ethylhexyl)-5-methyl-1H-benzotriazol-1-methylamine, 2,2'-[[(5-methyl-1H-benzotriazol-1-yl)methyl]imino]diethanol, and 6-methyl-benzotriazole were used as inhibitors. The remainder was water. Table 3 Example 18 Example 19 Example 20 Example 21 Example 22 Example 23 Example 24 4-Methylmorpholine 4-oxide 10 10 10 10 10 10 10 trans-1,2-cyclohexyl diazonium tetraacetate tetraammonium 0.1 0.1 0.1 0.1 0.1 0.1 0.1 BDG 30 30 30 30 30 30 30 DMSO 10 10 10 10 10 10 10 BTA 4 1 0 0 1 1 1 N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methylamine 0 0.1 0.1 0.2 0.2 0 0 N,N-bis(2-ethylhexyl)-5-methyl-1H-benzotriazole-1-methylamine 0 0 0.2 0.2 0.2 0 0 2,2'-[[(5-methyl-1H-benzotriazol-1-yl)methyl]imino]diethanol 0 0 0 0 0 0.2 0.2 6-Methylbenzotriazole 0 0 0 0 0.5 0 0.5 Composition: _{H₂O₂ volume} ratio 1:1 1:1 1:1 1:1 1:1 1:1 1:1 Cu (Å/min) 4 2 0.8 0.6 0.2 0.2 0.2 Co (Å/min) 2.1 1.2 0.2 0.2 0.2 0.2 0.1 Ru (Å/min) 0 0 0 0 0 0 0 TiN (Å/min) 173 175 168 170 177 181 181

The results in Table 3 show that the Cu/Co E/R decreases significantly with different inhibitor combinations, while maintaining a similar TiN E/R. No Ru E/R was detected. This means that with appropriate inhibitor combinations, Cu/Co/Ru protection can be achieved without compromising TiN E/R.

Examples 25-28

The role of buffer

In Examples 25-28, 4-methylmorpholine 4-oxide was used as the organic amine, trans-1,2-cyclohexyl diazonotetraacetic acid tetraammonium as the activator, BDG as the glycol ether, DMSO as the aprotic solvent, BTA, 2,2'-[[(5-methyl-1H-benzotriazol-1-yl)methyl]imino]diethanol and 5-methyl-benzotriazole as inhibitors, and one or more of TMAH (tetramethylammonium hydroxide), TEAH (tetraethylammonium hydroxide), ammonium hydroxide, diethylene glycolamine and triethylene glycolamine as buffers. The remainder was water. Table 4 Example 25 Example 26 Example 27 Example 28 4-Methylmorpholine 4-oxide 10 10 10 10 Tetraammonium trans-1,2-cyclohexyl diazonotetraacetic acid 0.1 0.1 0.1 0.1 TMAH (Tetramethylammonium hydroxide) 0 0 0 0 TEAH (Tetraethylammonium Hydrogen Oxide) 0 0 0 0 ammonium hydroxide 0 0.2 0 0 Diethylene glycolamine 0 0 0.48 0 Triethylene glycolamine 0 0 0 0.42 BDG 30 30 30 30 DMSO 10 10 10 10 BTA 1 1 1 1 2,2'-[[(5-methyl-1H-benzotriazol-1-yl)methyl]imino]diethanol 0.2 0.2 0.2 0.2 6-Methylbenzotriazole 0.5 0.5 0.5 0.5 Composition: _{H₂O₂ volume} ratio 1:1 1:1 1:1 1:1 pH 6.3 7.1 7.1 7.1 Cu (Å/min) 0.2 0.2 1.5 1.2 Co (Å/min) 0.1 0.1 1.8 1.3 Ru (Å/min) 0 0 0 0 TiN (Å/min) 181 246 210 210

The results in Table 4 show that the pH decreased significantly when no buffer was used (Example 25), which also led to a decrease in TiN E/R. Furthermore, with the use of appropriate combinations of buffers, Cu/Co/Ru and good TiN E/R protection can be achieved.

Examples 29-34

Composition: The role of _{H₂O₂ volume} ratio

In Examples 29-34, 4-methylmorpholine 4-oxide was used as the organic amine, trans-1,2-cyclohexyl diazonium tetraacetate tetraammonium as the activator, BDG as the ethylene glycol ether, DMSO as the aprotic solvent, BTA as the inhibitor, and no buffer was used. The remainder was water. Table 5 Example 29 Example 30 Example 31 Example 32 Example 33 Example 34 4-Methylmorpholine 4-oxide 10 10 10 10 10 10 trans-1,2-cyclohexyl diazonium tetraacetate tetraammonium 0.2 0.2 0.2 0.2 0.2 0.2 BDG 35 35 35 35 35 35 DMSO 10 10 10 10 10 10 BTA 1.5 1.5 1.5 1.5 1.5 1.5 Composition: _{H₂O₂ volume} ratio 22:1 5:1 2:1 1:1 1:2 1:5 pH 7 6.7 6.5 6.3 6.3 6.2 Cu 0.1 0.3 0.8 1.2 2.1 2.3 Co 0.1 0.7 0.9 1.3 1.8 2.5 Ru (Å/min) 0 0 0 0 0 0 TiN 15 61 98 110 108 93

The results in Table 5 show that the TiNE/R ratio increases with the amount _{of H₂O₂} added in the volume ratio. The best TiNE/R and Cu/Co/Ru protection can be obtained when the composition/ _{H₂O₂ ratio} is about 1:1.

Examples 35-43

The role of solvent

In Examples 35-43, 4-methylmorpholine 4-oxide was used as the organic amine, trans-1,2-cyclohexyl diazonotetraacetic acid tetraammonium as the activator, DMSO as the aprotic solvent, BTA, 2,2'-[[(5-methyl-1H-benzotriazol-1-yl)methyl]imino]diethanol and 5-methyl-benzotriazole as inhibitors, and TMAH (tetramethylammonium hydroxide), TEAH (tetraethylammonium hydroxide) and ammonium hydroxide as buffers. Meanwhile, butyl ethylene glycol, butyl triethylene glycol, BDG, n-hexyl diethylene glycol, n-hexyl ethylene glycol and dipropylene glycol monomethyl ether were used as ethylene glycol ethers. The remainder was water. Table 6 Example 35 Example 36 Example 37 Example 38 Example 39 Example 40 Example 41 Example 42 Example 43 4-Methylmorpholine 4-oxide 10 10 10 10 10 10 10 10 10 trans-1,2-cyclohexyl diazonium tetraacetate tetraammonium; 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 TMAH (Tetramethylammonium hydroxide) 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 TEAH (Tetraethylammonium Hydrogen Oxide) 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 ammonium hydroxide 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 Ethylene glycol monobutyl ether 30 0 0 0 0 0 20 0 0 Butyltriethylene glycol 0 30 0 0 0 0 10 0 0 BDG (Butyl diethylene glycol) 0 0 30 0 0 0 10 10 10 n-Hexyldiethylene glycol 0 0 0 20 0 0 0 10 0 n-Hexylethylene glycol 0 0 0 0 20 0 0 0 10 Dipropylene glycol monomethyl ether 0 0 0 0 0 20 0 10 10 DMSO 10 10 10 15 15 15 10 10 10 BTA 1 1 1 1 1 1 1 1 1 2,2'-[[(5-methyl-1H-benzotriazol-1-yl)methyl]imino]diethanol 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 6-Methylbenzotriazole 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Composition: _{H₂O₂ volume} ratio 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 1:1 pH 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 6.7 Cu (Å/min) 0.2 0.2 0.2 1.1 1.2 1.2 0.9 0.7 1 Co (Å/min) 0.8 0.6 0.6 0.2 0.7 0.7 1.2 1.2 1.1 Ru (Å/min) 0 0 0 0 0 0 0 0 0 TiN (Å/min) 100 210 192 193 183 178 187 190 211

The results in Table 6 show that different combinations of solvents (especially glycol ethers) will result in different TiN and Co/Cu E/R ratios.

Therefore, with the use of appropriate solvent combinations, good protection of TiN E/R and Cu/Co/Ru can be achieved.

The results in the table above show that the composition used allows control over the etching rate ratio of TiN and Co and/or Cu and/or Ru.

In this disclosure, the words “one” or “a” should be understood to include both the singular and plural. Conversely, where appropriate, any reference to plural items should include the singular.

As will be seen from the foregoing, many modifications and variations can be made without departing from the true spirit and scope of the novel concepts of this disclosure. It should be understood that there is no limiting intent or should be presumed that the specific embodiments or examples shown are limited. This disclosure is intended to cover all such modifications falling within the scope of the appended claims.

11: Residue containing C, O, F, Ti, and N 12: Cu layer 13: Co or Ru barrier layer 14: Low-k material 15: TiN 51: Sample 52: Reagent

[Figure 1] illustrates the general structure on the wafer within the first metallization layer, specifying a residue 11 containing C, O, F, Ti, and N, a Cu layer 12, a Co or Ru barrier layer 13, a low-k material 14, and TiN 15. [Figure 2] illustrates the removal of the residue 11 containing C, O, F, Ti, and N within the first metallization layer, as well as partial and complete etching of TiN 15. [Figure 3] schematically depicts the experimental setup used in the experiments (thickness measurement; etching rate; cleaning performance (SEM, TEM, XPS...)).

11: Residue containing C, O, F, Ti, and N 12: Cu layer 13: Co or Ru barrier layer 14: Low-k material 15: TiN

Claims (20)

A composition comprising: a) 0.1 to 15 wt% of an organic amine, based on the total weight of the composition, wherein the organic amine is selected from the following: 4-methylpyridine N-oxide; 2-methylpyridine N-oxide; 4-methoxypyridine N-oxide hydrate; 4-chloropyridine N-oxide; 8-methylquinoline N-oxide; 1-dodecaneamine N,N-dimethyl-N-oxide; 4-methylmorpholine 4-oxide; 1-tetradecaneamine N,N-dimethyl-N _{-oxide; C10-16 alkyldimethylamine} oxide; C _12-18 alkyldimethyl-N-oxide; pyridine 1-oxide; decylamine, N,N-dimethyl-N-oxide; hexadecylamine N,N-dimethyl-N-oxide; b) one or more inhibitors, from 0.01 to 6 wt% of the total weight of the composition, wherein the inhibitor is selected from: benzotriazole; 5-alkylbenzotriazole; 6-alkylbenzotriazole; 5-amino-benzotriazole; 6-amino-benzotriazole; 1-(methoxymethyl)-1H-benzotriazole; 1H-benzotriazole-1-methanol; 1-(chloromethyl)-1H-benzotriazole; 5-phenyl-benzotriazole; N,N-bis(2-ethylhexyl)-4-methyl-1H-benzotriazole-1-methylamine; N,N-bis(2-ethylhexyl)-5-methyl 1H-benzotriazole-1-methylamine; 2,2'-[[(5-methyl-1H-benzotriazole-1-yl)methyl]imino]diethanol;5-nitro-benzotriazole; benzotriazole carboxylic acid; 1-amino-1,2,4-triazole; hydroxybenzotriazole; 2-(5-amino-pentyl)-benzotriazole; 1-amino-1,2,3-triazole; 1-amino-5- Methyl-1,2,3-triazole; 3-amino-1,2,4-triazole; 5-amino-1,2,4-triazole; 3-isopropyl-1,2,4-triazole; 3,5-diamino-1,2,4-triazole; 5-phenylthio-benzotriazole; 5-halogen-benzotriazole; 6-halogen-benzotriazole; and 4-amino-4H-1,2,4-triazole, wherein the alkyl group =-C _n H _2n+1 , where n = 1-6, and halogen = F, Cl, Br, or I; c) 0.01 to 5 wt% of one or more buffers, selected from the following: ammonium hydroxide; methanolamine; ethanolamine; triethanolamine; polyethylene glycolamine; diethylene glycolamine; triethylene glycolamine; 1,3,5-tris(dimethylaminopropyl)-hexahydrotriazine; d) 0.01 to 3 wt% of an activator, selected from the following: disammonium hydrogen phosphate; and ammonium phosphate; e) one or more ethylene glycol ethers; f) optional aprotic solvent; and g) water. According to the composition of claim 1, said organic amine is selectable from 4-methylmorpholine 4-oxide. According to the composition of claim 1, the buffer may be present in the composition of the invention in an amount ranging from 0.5 to 2 wt% based on the total weight of the composition. According to the composition of claim 1, the inhibitor is selected from benzotriazole; 5-alkylbenzotriazole; and 6-alkylbenzotriazole, wherein alkyl = -C _n H _2n+1 , and n = 1-6. According to the composition of claim 1, the inhibitor may be present in the composition in an amount ranging from 0.5 to 2 wt% based on the total weight of the composition. According to the composition of claim 1, the activator may be present in the composition of the invention in an amount ranging from 0.1 to 1 wt% based on the total weight of the composition. According to the composition of claim 1, the ethylene glycol ether may be selected from the following: butyl ethylene glycol, butyl diethylene glycol, butyl triethylene glycol, n-hexyl diethylene glycol, n-hexyl ethylene glycol, 2-hexyloxy-1-ethanol, tetrahydrofurfuryl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monobenzyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol monomethyl ether Ethers, triethylene glycol dimethyl ether, polyethylene glycol monomethyl ether, diethylene glycol methyl ethyl ether, triethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monobutyl ether, propylene glycol, monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoisopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol diisopropyl ether, tripropylene glycol monomethyl ether, 1-methoxy-2-butanol, 2-methoxy-1-butanol, 2-methoxy-2-methylbutanol, 1,1-dimethoxyethane, and 2-(2-butoxyethoxy)ethanol. According to the composition of claim 1, the amount of the ethylene glycol ether present in the composition of the present invention, based on the total weight of the composition, ranges from 1 to 60 wt%. According to the composition of claim 1, the amount of the ethylene glycol ether present in the composition of the present invention, based on the total weight of the composition, ranges from 10 to 50 wt%. According to the composition of claim 1, said aprotic solvent may be selected from the following: dimethyl sulfoxide, cyclobutane, propylene carbonate, dimethylacetamide, N-methyl-2-pyrrolidone, dimethylformamide, or mixtures thereof. According to the composition of claim 10, the amount of the aprotic solvent present in the composition of the invention, based on the total weight of the composition, ranges from 1 to 50 wt%. Use of a combination of a composition according to any one of claims 1 to 11 with an oxidant for adjusting the etching rate of Cu/Co/Ru and TiN and/or removing organic and/or inorganic residues. According to the intended use of claim 12, the oxidant can be selected from hydrogen peroxide, ozone water, or persulfate. According to the intended use of claim 13, the oxidant can be selected from hydrogen peroxide. According to the intended use of claim 12, the oxidant can be added in a volume ratio of the composition comprising components a) to g) to the oxidant ranging from 65:1 to 1:5. According to the purpose of claim 15, the oxidant can be added in a volume ratio of the composition comprising components a) to g) to the oxidant ranging from 33:1 to 1:2. According to the purpose of claim 15, the oxidant can be added in a volume ratio of the composition comprising components a) to g) to the oxidant ranging from 22:1 to 1:1. A reagent kit comprising: a composition according to any one of claims 1 to 11; and an oxidizing agent. The reagent kit according to claim 18, wherein the oxidant can be selected from hydrogen peroxide, ozone water, or persulfate. The reagent kit according to claim 19, wherein the oxidant can be selected from hydrogen peroxide.